KR100738319B1 - Method for Manufacturing compensation Optical Device for VA mode with using Nematic Crystal and compensation Optical Device for VA mode with using Nematic Crystal using thereof - Google Patents

Abstract

The present invention is to provide a method for manufacturing a compensation optical element for VA using a nematic liquid crystal, (a) 100% by weight of the alignment film coating solution in which an alignment film coating composition comprising an alignment film resin and a curing agent is mixed in a solvent, Iii) The alignment film resin is 10% to 45% by weight ii) The curing agent is mixed with 0.1% to 10% by weight of the alignment film coating solution, the rotation speed is 50rpm to 5,000rpm, the rotation time is 10 seconds to 500 seconds An alignment film forming step of spin coating the A plate attached to the polarizing film using a continuous rotary coating machine, and then drying and ultraviolet curing to form an alignment film; (b) a rubbing step of rubbing the alignment film formed in the step in a horizontal direction; And (c) a liquid crystal coating solution in which a nematic liquid crystal is mixed at 5% by weight to 50% by weight on the rubbed alignment layer with a rotation speed of 50 rpm to 6,000 rpm, and a rotation time of 10 seconds to 600 seconds. After spin-coating, the liquid crystal layer is formed by drying and ultraviolet curing to form a liquid crystal layer.

VA, nematic, liquid crystal, coating, spin, spin, optical

Description

Method for manufacturing compensation optical device using V and nematic liquid crystal {Method for Manufacturing compensation Optical Device for VA mode with using Nematic Crystal and compensation Optical Device for VA mode with using Nematic Crystal using

1 is a configuration diagram of a compensation optical element for VA using a nematic liquid crystal according to an embodiment of the present invention,

2 is a graph showing a phase difference change according to an incident angle with respect to a phase axis of a compensation optical device obtained in Example 1 of the present invention;

3 is a graph showing a phase difference change according to an incident angle with respect to a phase axis of a compensation optical device obtained in Example 2 of the present invention;

4 is a graph illustrating a change in phase difference according to an incident angle with respect to a phase axis of a compensation optical device obtained in Comparative Example 1;

5 is a graph showing a change in phase difference according to an angle of incidence with respect to a phase axis of a compensation optical device obtained in Comparative Example 2;

6 is a graph showing a change in phase difference with respect to omnidirectionalness of a compensation optical device obtained in Example 1 of the present invention;

7 is a graph showing a change in phase difference with respect to omnidirectionalness of a compensation optical device obtained in Example 2 of the present invention.

Explanation of symbols on the main parts of the drawings

100: polarizing film 200: pressure-sensitive adhesive

300: A-plate 400: alignment film

500: liquid crystal layer

The present invention relates to a method for manufacturing a compensation optical element for VA using a nematic liquid crystal and a VA optical element using the same, in particular a biaxial film attached to a polarizing film cut to a predetermined size by a spin-coating method. By coating an alignment film and a nematic liquid crystal on (nx ≠ ny ≠ nz), a thin film can be manufactured as a manufacturing method of an optical device capable of compensating the black state of VA-LCD (Vertical Aligned Liquid Crystal Display). In addition, the present invention relates to a method for manufacturing a compensation optical device for VA using a nematic liquid crystal which can improve the yield due to a reduction in the manufacturing process, and a compensation optical device for VA using the same.

In general, a liquid crystal display device has a structure in which a liquid crystal is injected between two substrates, and a light transmittance is controlled by adjusting an intensity of an electric field applied to the liquid crystal.

In this case, the liquid crystal material has birefringence in which the refractive indices of the molecules in the major axis direction and the minor axis direction are different from each other. The birefringence causes a difference in the refractive index felt by light depending on the position at which the liquid crystal display device is viewed. Therefore, the difference in the rate of change of the polarization state as the linearly polarized light passes through the liquid crystal, the amount of light and color characteristics when viewed from the position off the front is different from when viewed from the front. As a result, the liquid crystal display may experience a change in contrast ratio, color shift, gray inversion, and the like depending on the viewing angle.

Conventionally, negative C-plates and A-plates have been mainly used to compensate for the dark state of VA-LCD in the absence of voltage, and the compensation film is generally cyclo olefin, polycarbonate, TAC film. It has been used to uniaxially or biaxially. A method of using a negative C plate and an A-plate by placing two A-plates and a negative C-plate between the top glass and the top polarizer of the liquid crystal panel, and using two A-plates and a negative C-plate. How to place between the bottom glass and bottom polarizer of the liquid crystal panel, A-plate or negative C-plate between the top glass and top polarizer of the liquid crystal panel and between the bottom glass and bottom polarizer of the liquid crystal panel 1 There was a method of posting each one or each one.

However, the VA-LCD including the -C-Plate compensation film manufactured by the conventional stretching method has a disadvantage in that light leakage occurs at an inclination angle because the compensation of the dark state is not completely performed. In addition, A-plates prepared by different stretching methods were used to prevent black compensation and color change of the dark state, but this resulted in a reduction in the complexity and yield of the process, and an increase in thickness.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, and an object of the present invention is a biaxial stretched biaxially attached to a polarizing film cut to a predetermined size by a spin-coating method. By coating the alignment layer and the nematic liquid crystal on the film (nx ≠ ny ≠ nz), a compensation optical device capable of maximizing the effect by compensating the black state of the VA-LCD (Vertical Alignment-Liquid Crystal Display) To provide.

In addition, by adopting a method of coating the alignment film and the nematic liquid crystal on the biaxial film by using a spin coating method as a method of manufacturing the compensation optical element, it is possible to produce a thin and improved yield due to the reduction of the manufacturing process. It is to provide a method of manufacturing a compensation optical element for VA using a nematic liquid crystal.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail centering on a technical structure.

The method for manufacturing a compensation optical element for VA using nematic liquid crystal according to the present invention is cut to a predetermined size according to the size of a polarizing film and stretched to a polar film (hereinafter referred to as 'A-plate'). And coating the alignment layer on the A-plate, drying and curing to form an alignment layer; A rubbing step of performing a rubbing treatment on the alignment layer; And a liquid crystal layer forming step of coating, drying, and curing a nematic liquid crystal on the rubbed alignment layer.

A-plates used in the present invention include polycarbonate films, cycloolefin-based films, polymethylmethacrylate films, and the like.

Hereinafter, a step-by-step look at the manufacturing method of the compensation optical element for VA using the nematic liquid crystal according to the present invention.

(1) alignment film forming step

The alignment film is prepared by mixing an alignment film coating composition including an alignment film resin and a curing agent in a solvent to form a solution, followed by coating by spin coating on the A-plate, followed by drying and curing of the alignment film. .

1) alignment layer coating step

In the present invention, the alignment film coating composition comprising an alignment film resin and a curing agent is carried out by coating a solution of the prepared form with a solvent (hereinafter, 'alignment film coating solution') on the A-plate by spin coating.

The rotation speed and rotation time applied in the spin coating method of the present invention are as follows.

The rotation speed of the spin coating in the present invention is preferably 50rpm to 5,000rpm to coat a solution obtained by mixing the alignment film coating composition with a solvent, more preferably 100rpm to 4,000rpm. Even more preferred spin speeds range from 500 rpm to 3,000 rpm.

If the rotation speed of the spin coating is less than 50 rpm, the desired predetermined thin film may not be obtained, and the alignment layer may not be evenly applied to the surface of the A-plate attached to the polarizing film. In addition, when it is larger than 5,000 rpm, a difference in thickness occurs in the center portion and the outer portion of the alignment layer due to the high centrifugal force. In addition, the spin coating apparatus may be difficult to maintain a high rotational speed.

In addition, the spin time in the spin coating step of the present invention is preferably 10 seconds to 500 seconds, more preferably 30 seconds to 400 seconds. Even more preferably 60 to 300 seconds. The rotation time may vary depending on the viscosity of the solution in which the alignment film coating composition and the solvent are mixed and the thickness of the alignment film to be coated.

If the rotation time is less than 10 seconds, it is difficult to secure sufficient time to evenly apply the alignment film to the A-plate, and if it is more than 500 seconds, the economy is inferior.

It is preferable to use ultraviolet curable resin for the orientation film resin used by this invention. As the example, an unsaturated polyester resin, a polyfunctional acrylate resin, a polyfunctional methacrylate, a urethane acrylate, an epoxy acrylic resin, an epoxy acrylate resin or the like or a mixture of these can be used. Of course, if the alignment film resin usable in the present invention exhibits the same effect, the range is not limited to the resins listed above.

In addition, the said alignment film resin uses the compound which has a 1 or more polar group and 1 or more functional group in a molecule | numerator. The at least one polar group is preferably at least one of a hydroxy group, an amino group, a urethane group or an isocyanate ring in the compound, and different polar groups may be present.

The content of the alignment film resin is preferably 10 wt% to 45 wt% in 100 wt% of the alignment film coating solution. More preferably, it is 15 to 40 weight%. If the content of the alignment film resin is less than 10% by weight, the hardness is low enough to form the alignment film, if more than 45% by weight is more than necessary, the alignment film resin is included, there is a disadvantage that the economical efficiency.

In addition, the curing agent may be used by selecting one curing agent or a mixture of two or more according to the type of alignment film resin, preferably isocyanate compound, epoxy compound, aziridine compound, metal chelate compound, metal alkoxide metal salt, amine A compound, a hydrazine compound, etc. are used individually or in mixture.

In this invention, since ultraviolet curable resin is used as an orientation film resin, it is preferable to use an ultraviolet curable hardening | curing agent. In addition, it is preferable to adjust and select the type, size, content, etc. of the curing agent according to the type, physical and chemical properties of the curable resin to be used.

Isocyanate compounds in the present invention are trimethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, diphenylmethane isocyanate, xylene diisocyanate aromatic diisocyanate compounds such as diisocyanate, aliphatic diisocyanate such as hexamethyl diisocyanate, and the like are used alone or in combination.

In addition, the epoxy compound in the present invention is a polyethylene glycol diglycidyl ether (diglycidyl ether), diglycidyl ether (diglycidyl ether), trimethylol propane triglycidyl ether (trimethylol propane triglycidyl ether) and the like alone Or mixed.

The curing agent used to form the alignment film of the present invention is preferably used 0.1% to 10% by weight, more preferably 0.5% to 5% by weight relative to 100% by weight of the alignment film coating solution.

In the present invention, the curing agent is an additive used to control the molecular weight or the chain structure of the alignment layer coating composition. When the curing agent is used in the above-described range, the effect of suppressing phase separation and the like is prominent. When the content of the curing agent is less than 0.1% by weight, it is difficult to expect the function of the curing agent, and when the content of the curing agent is greater than 10% by weight, the content of the curable resin is relatively low, making it difficult to increase hardness.

In addition, the solvent used in the alignment film coating step may be suitably mixed with the alignment film coating composition (composition comprising a alignment film resin and a curing agent). A representative example is Iso Propyl Alcohol (IPA).

And the viscosity of the alignment film coating solution containing the alignment film resin is preferably 1cps to 500cps. When the viscosity is 1 cps or less, the thickness of the alignment film to be manufactured may be controlled to be thin. However, the hardness of the alignment film may be lowered, so that it may be insufficient to perform the function of the alignment film. It is difficult to control the thickness of the alignment film, and a problem arises in that a part of the film becomes thick.

2) Alignment layer drying step

In the alignment film drying step, a process of drying the A-plate to which the alignment film is uniformly applied in step 1) is performed. That is, in the alignment film drying step, the solvent applied in the alignment film coating step is volatilized.

The drying temperature performed in the drying step is preferably 20 ° C to 70 ° C, more preferably 25 ° C to 60 ° C. If the drying temperature is lower than 20 ° C, it takes longer to remove the solvent, and if the drying temperature is higher than 70 ° C, the physical properties of the alignment layer may be affected.

Moreover, as for drying time, about 15 second-about 300 second are preferable. More preferably 55 to 200 seconds, still more preferably 60 to 100 seconds. If the drying time is less than 15 seconds, the effect of drying does not appear properly, and drying for more than 300 seconds may affect the physical properties. In this case, drying in a continuous rotary coating machine at the same rotation speed as in step 1) can further shorten the drying time.

3) Alignment film curing step

In the alignment film curing step, ultraviolet light (UV) is applied to the alignment film dried in the step 2) to form an alignment film.

The UV curing step is carried out to completely attach the dried alignment layer to the A-plate and to completely remove the solvent that could not be removed in the drying process.

In addition, the energy range of UV is preferably 250mJ / cm ² to 600mJ / cm ² . If the amount of energy irradiation is 250mJ / cm ² or less, sufficient curing effect does not appear, if the 600mJ / cm ² or more may affect the physical properties of the alignment layer.

The curing time is relatively determined corresponding to the energy irradiation amount of UV, the curing time is preferably 45 seconds to 130 seconds. If the curing time is 45 seconds or less, the effect of curing does not appear sufficiently. If the curing time is 130 seconds or more, the physical properties and durability of the alignment film may be affected, thereby degrading the function of the alignment film. The above-mentioned ultraviolet curing uses ultraviolet rays emitted from light sources such as ultra high temperature mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp and the like.

It is preferable to form the said oriented film so that the thickness may be set to 0.01 micrometer-5 micrometers. More preferably, they are 0.05 micrometer-3 micrometers. If the thickness is thicker than 5 μm, the thickness of the VA compensation film becomes thicker than necessary, and if the thickness is thinner than 0.01 μm, the nematic liquid crystals, which will be described later, cannot be properly aligned to compensate for dark state or color change of the VA-LCD. The disadvantage is that it does not perform properly.

(2) rubbing

In the rubbing step, the alignment film formed in the step (1) is passed through the rubbing device to perform a process of helping to orient the surface in a predetermined direction. Although the rubbing step is not particularly limited, it is preferable that the process is smooth since it affects the orientation and uniformity of the liquid crystal compound later. In the rubbing treatment performed in the rubbing step, for example, a rubbing roll is manufactured by attaching a velvet-shaped cloth in which fibers such as lenyon, nylon, cotton, and aramid are attached to a roll, and the organic material is coated in a state where the roll is rotated at high speed. How to treat the surface. Or a rubbing process can be performed by carrying out high speed rotation in the state which fixed the rubbing roll, and conveying a film, making contact with a rubbing roll. Conditions for rubbing treatment include the type of polymer film or plastic film or cloth to be used, the diameter of the rubbing roll or the rotation speed and rotation direction of the rubbing roll, the moving speed of the polymer film or rubbing roll, and the pressure of the rubbing roll to the polymer film. It is set differently according to the degree. It is preferable that the rubbing is a rubbing treatment in the horizontal direction. Due to the rubbing treatment in the above direction, the liquid crystal layer to be described later serves as a negative C-plate.

(3) liquid crystal layer forming step

In the present invention, the liquid crystal layer forming step is performed by coating, drying, and curing the liquid crystal layer by a spin coating method on the alignment layer rubbed in the rubbing step.

1) Liquid Crystal Layer Coating Step

In the liquid crystal layer coating step, the liquid crystal composition containing the nematic liquid crystal is coated on the alignment layer by spin coating in the form of a solution (hereinafter, 'liquid crystal coating solution') in a solvent.

Nematic liquid crystals are liquid crystals that have an order of orientation in the direction assuming the molecular axis, although there is no regularity in the molecular position. Nematic liquid crystals are generally ferroelectric because the polarization is canceled because the directions of molecules are almost equal to up and down. Say that.

The rotation speed and rotation time applied in the spin coating method of the present invention are as follows.

In the present invention, it is preferable to perform the spin coating at a rotational speed of 50 rpm to 6,000 rpm, more preferably 100 rpm to 4,000 rpm.

If the rotation speed of the spin coating is less than 50 rpm, the desired predetermined thin film may not be obtained and the liquid crystal layer may not be evenly applied to the surface of the alignment layer. In addition, when greater than 6,000 rpm, the difference in thickness occurs in the center and the outer portion of the liquid crystal layer due to the high centrifugal force. In addition, in order to maintain a high rotational speed can be difficult to spin coating apparatus and affect the durability of the liquid crystal layer itself.

In addition, the rotation time in the spin coating step of the present invention is preferably 10 seconds to 600 seconds, more preferably 30 seconds to 400 seconds. The rotation time may vary depending on the viscosity of the liquid crystal coating solution in which the liquid crystal composition and the solvent are mixed, and the thickness of the liquid crystal layer to be coated.

If the rotation time is less than 10 seconds, it is difficult to ensure sufficient time for evenly applying the liquid crystal layer to the rubbed alignment film, and if it is more than 600 seconds, the economy is inferior.

As the nematic liquid crystal used in the present invention, a predetermined amount of an optically active component is added to a liquid crystalline polymer which exhibits uniform, monodomain nematic alignment properties on the alignment substrate and which can easily fix the alignment state. It is preferable to use one curable nematic liquid crystalline polymer (monomer form becomes polymer form after the curing step described later). The reason for using the curable nematic liquid crystalline polymer is that it must be used as a compensation film.

As the optically active component, any one can be used as long as it exhibits optical activity, but it is preferable to use an optically active polymer compound or a polymer composition. As long as it has an optically active group in a molecule | numerator, all can be used, It is preferable from a viewpoint of compatibility with the said liquid crystalline polymer that it is an optically active liquid crystalline high molecular compound or a liquid crystalline polymer composition. Examples of the liquid crystalline polymers include polyacrylates, polymethacrylates, polymalonates, polysiloxanes, polyesters, polyamides, polyesteramides, polycarbonates, polypeptides, celluloses, and compositions based on these liquid crystalline polymers. Can be. Especially, the liquid crystalline polyester which is optically active of an aromatic principal is contained as a preferable example.

Moreover, as a liquid crystalline polymer which has an optically active group in a molecule | numerator, Polyacrylate which has an optically active group in the side chain of polyester, polyimide, polyamide, polycarbonate, polyesterimide, or a polymer which has an optically active group in a polymer main chain, Polymethacrylate, polymalonate, polysiloxane, etc. are mentioned as an example. Among them, liquid crystal polyesters having good orientation and relatively easy synthesis are preferred. Examples of the structural unit of the polymer include aromatic or aliphatic diol units, aromatic or aliphatic dicarboxylic acid units, and aromatic or aliphatic hydroxycarboxylic acid units.

In addition, the solvent used to dissolve the liquid crystal composition comprising the nematic liquid crystal is a halogenated hydrocarbon such as chloroform, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, o-dichlorobenzene, these and phenols And mixed solvents, kentones, ethers, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, sulfolane, cyclohexanone, xylene, toluene and the like.

The content of the liquid crystal composition is preferably from 5% by weight to 50% by weight, more preferably from 10% by weight to 40% by weight in 100% by weight of the liquid crystal coating solution.

If the content of the liquid crystal composition is less than 5% by weight, compensation functions (view angle compensation, gradation inversion compensation, color compensation, etc.) cannot be properly performed as a compensation film for VA, and when the content is more than 50% by weight, the liquid crystal composition is more than necessary. It not only makes the control of the process difficult, but also has the disadvantage of low economic efficiency.

In addition, the optically active component is preferably 5 parts by weight to 15 parts by weight with respect to 100 parts by weight of the nematic liquid crystalline polymer. More preferably, they are 8 weight part-13 weight part. If the content of the optically active ingredient is 5 parts by weight or less, the optically active function cannot be properly performed, and more than 15 parts by weight is meaningless because there is no difference in effect.

In addition, the liquid crystal coating solution preferably has a viscosity of 1 cps to 600 cps, more preferably 10 cps to 450 cps. Even more preferred is 50cps to 300cps.

When the viscosity of the liquid crystal coating solution is less than 1 cps, it is difficult to easily apply the liquid crystal coating solution due to the low adhesive strength. When the viscosity of the liquid crystal coating solution is larger than 600 cps, the adhesive force is too large to control the process.

2) drying step

The drying step is performed to remove the solvent applied to the liquid crystal layer in the liquid crystal layer coating step.

The drying temperature performed in the drying step is preferably 15 ℃ to 60 ℃, more preferably 25 ℃ to 55 ℃. If the drying temperature is lower than 15 ° C, it takes longer to remove the solvent, and if the drying temperature is higher than 60 ° C, the physical properties of the liquid crystal layer may be affected.

Moreover, as for drying time, about 15 second-about 300 second are preferable. More preferably 55 to 200 seconds, still more preferably 60 to 100 seconds. If the drying time is less than 15 seconds, the effect of drying does not appear properly, and drying for more than 300 seconds may affect the physical properties. In this case, drying in a continuous rotary coating machine at the same rotation speed as in step 1) can further shorten the drying time.

3) liquid crystal layer curing step

In the liquid crystal layer curing step, ultraviolet light (UV) is applied to the liquid crystal layer dried in the drying step to form a liquid crystal layer.

The hardening of the liquid crystal layer is performed to completely attach the dried liquid crystal layer to the alignment layer and to completely remove the solvent that may not be removed in the drying process.

In addition, the energy range of UV is preferably 250mJ / cm ² to 600mJ / cm ² . If the amount of energy irradiation is 250mJ / cm ² or less, sufficient curing effect does not appear, if the 600mJ / cm ² or more may affect the physical properties of the alignment layer.

The curing time is relatively determined corresponding to the energy irradiation amount of UV, the curing time is preferably 45 seconds to 130 seconds. If the curing time is 45 seconds or less, the effect of curing does not appear sufficiently. If the curing time is 130 seconds or more, the physical properties and durability of the liquid crystal layer may be affected, thereby degrading the function of the liquid crystal layer. The above-mentioned ultraviolet curing uses ultraviolet rays emitted from light sources such as ultra high temperature mercury lamp, high pressure mercury lamp, low pressure mercury lamp, carbon arc, xenon arc, metal halide lamp and the like.

The liquid crystal layer is preferably formed to have a thickness of 0.01 μm to 40 μm. More preferably, they are 0.1 micrometer-20 micrometers. If the thickness of the liquid crystal layer is thinner than 0.01㎛ it is difficult to perform the desired viewing angle compensation function, if the thickness is more than 40㎛ has a disadvantage that the thickness of the viewing angle compensation film.

The structural diagram of the compensation optical device for VA using the nematic liquid crystal manufactured through the above process is shown in FIG. 1. As shown, in the compensation optical device for VA using nematic liquid crystal, an A plate 300, which is a biaxial film, is attached to the polarizing film 100 by the adhesive 200, and the alignment layer 400 is disposed on the A plate 300. ) Is coated and the liquid crystal layer 500 including the nematic liquid crystal is coated thereon. This makes the manufacturing process simpler than compensating optical elements for VA by the conventional stretching method. The liquid crystal layer 500 plays a role of a negative C-plate manufactured by a conventional stretching method (compensation for phase difference in thickness direction).

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the following examples are only examples of the present invention and the present invention is not limited to these examples.

Example 1

1) After making a polarizing film in the usual way, cut it into 500mm horizontally and vertically, and then use Sekisui's cyclo olefin biaxial film S-SINA (50/80) ^ⓡ using adhesive on one side of the polarizing film in a continuous rotary coating machine. Attach the product. The S-SINA (50/80) ^ⓡ product to the alignment layer on the resin is a polyfunctional acrylate-based and polyfunctional meth as alignment film of the acrylate resin-based acrylic dipentaerythritol acrylate with (Nippon Kayaku Kayard D-310) and 35 weight% of alignment film resin which mixed pentaerythritol triacrylate (Kayarad PET-30 by Nippon Kayaku Co., Ltd.) by weight ratio 9: 1, and 3 weight% of trimethylene diisocyanate as a hardening | curing agent, The alignment film resin + hardener) is dissolved in isopropyl alcohol to coat the solution by spin coating. At this time, the rotation speed was set at a speed of 200 rpm, and the time was performed for 1 minute. Then, drying and ultraviolet curing were performed to form an alignment film with a thickness of 3 m. The drying was carried out at 25 ° C., and for 1 minute. Curing was performed by irradiation with 300mJ / cm ² UV.

2) The alignment film was subjected to a rubbing treatment in the horizontal direction.

3) As the liquid crystal, a coating was performed using a nematic curable liquid crystal solution (Merck's RMS04-020). The nematic curable liquid crystal solution (Merck's RMS04-020) is one in which 38% by weight of the nematic liquid crystal is dissolved in a mixed solvent of toluene and cyclohexanone (liquid crystal coating solution). The liquid crystal coating solution was coated on the alignment layer for 1 minute at a rotational speed of 250 rpm in a continuous rotary coater and dried at 25 ° C. for 1 minute, followed by ultraviolet curing with energy of 300 mJ / cm ² to form a liquid crystal layer. A compensation optical device was manufactured to have a thickness of 3 μm.

Example 2

A viewing angle compensation optical device was manufactured under the same conditions as in Example 1 except that the thickness of the liquid crystal layer was increased to 5 μm.

Comparative Example 1

The A-plate produced by the conventional stretching method was attached to the polarizing film (polycarbonate film used).

Comparative Example 2

The negative C-plate produced by the conventional drawing method was attached to the polarizing film and used (using cycloolefin film).

Table 1 shows the refractive index, refractive index correlation, surface direction, and thickness direction phase difference with respect to the phase axis of the compensation optical elements obtained in Examples 1, 2, Comparative Example 1, and Comparative Example 2.

Item Nx Ny Nz Refractive index correlation Planar phase difference (R0) Thickness Direction Retardation (Rth) Example 1 1.67206 1.67110 1.66666 Nx> Ny> Nz 48.0 258.0 Example 2 1.67241 1.67146 1.66307 Nx> Ny> Nz 47.7 368.3 Comparative Example 1 1.49876 1.49760 1.49615 Nx> Ny> Nz 50.2 87.2 Comparative Example 2 1.47099 1.47097 1.46894 Nx = Ny> Nz 2.3 120.6

(Nx means the refractive index in the x-axis, Ny means the refractive index in the y-axis, and Nz means the refractive index in the z-axis.)

The surface direction retardation of the compensation optical elements obtained in Examples 1, 2 and Comparative Example 1 is almost similar. This is because the compensating optical elements obtained in Examples 1, 2, and Comparative Example 1 are each provided with an A plate for compensating the phase direction difference. In contrast, the compensating optical element obtained in Comparative Example 2 is a negative C-plate, and thus has a weak function of compensating the retardation in the plane direction.

In addition, the compensation optical element obtained in Comparative Example 1 is significantly lower in the thickness direction retardation than the compensation optical element obtained in Examples 1, 2, and Comparative Example 2. The thickness direction retardation is remarkably inferior to the rest of the compensating optical element because the A plate using only the surface direction retardation is used without consideration. And the thickness direction retardation value is larger than the compensation optical element obtained in Example 2, and the compensation optical element obtained in Example 1, and the compensation optical element obtained in Example 1 is larger than the compensation optical element obtained in Comparative Example 2. The larger thickness direction retardation of the compensation optical elements obtained in Examples 1 and 2 than Comparative Example 2 means that the retardation in the thickness direction of a larger range can be compensated. The compensation optical element obtained in Example 2 has a larger thickness direction retardation than the compensation optical element obtained in Example 1 because the thickness of the liquid crystal layer is formed thicker than that in Example 1.

2 to 5 are graphs showing changes in phase difference according to incident angles of compensation optical elements obtained in Examples 1, 2, Comparative Example 1, and Comparative Example 2. FIG. As shown in the figure, it can be seen that all four graphs have a symmetrical shape. This means that the viewing angle can be improved to the same extent on both the left and right sides.

6 and 7 show phase differences of the compensation optical elements obtained in Examples 1 and 2 according to the omnidirectional. The phase difference shown in the graph is a value opposite to the phase difference delayed in the liquid crystal for VA. That is, by using an optical element with a compensation film having a phase difference opposite to that shown in the liquid crystal for VA, the viewing angle can be further improved.

In the above, this invention was demonstrated in detail with reference to an Example and a comparative example centering on a structure. However, the scope of the present invention is not limited to the above embodiments, but may be embodied in various forms of embodiments within the scope of the appended claims. Without departing from the gist of the invention as claimed in the claims, any person of ordinary skill in the art is deemed to be within the scope of the claims underlying the present invention to the extent possible for various modifications.

In addition, the preferred range, more preferred range, and even more preferred range limitation in the present invention are intended to maximize the effect even more, and more satisfactory technical effects can be obtained by narrowing the limited range.

As described above, the method for manufacturing a compensation optical element for VA using the nematic liquid crystal according to the present invention and the VA optical element using the same are attached to a polarizing film cut to a predetermined size by a spin-coating method. By coating the alignment film and the nematic liquid crystal on the biaxial film (nx ≠ ny ≠ nz), the manufacturing method of the compensation film that can maximize the black state compensation of the vertical alignment liquid crystal display (VA-LCD) The advantage is that it can be manufactured.

In addition, the manufacturing process using the spin coating method of the present invention has the advantage that it can be produced in a thin film than the manufacturing process in the stretching method, the production process is simple and the yield can be improved.

Claims (11)

(a) In 100 weight% of the orientation film coating solution which mixed the orientation film coating composition comprised including the orientation film resin and a hardening | curing agent in the solvent, Iii) 10 wt% to 45 wt% of the alignment film resin Ii) the A-plate attached to the polarizing film using a continuous rotary coating machine wherein the curing agent is mixed with 0.1 wt% to 10 wt% of the alignment layer coating solution at a rotation speed of 50 rpm to 5,000 rpm and a rotation time of 10 seconds to 500 seconds. Spin-coating on, followed by drying and ultraviolet curing to form an alignment film; (b) a rubbing step of rubbing the alignment film formed in the step in a horizontal direction; And (c) a liquid crystal coating solution in which the nematic liquid crystal is mixed at 5% by weight to 50% by weight on the rubbed alignment layer using a continuous rotary coating machine having a rotation speed of 50 rpm to 6,000 rpm and a rotation time of 10 seconds to 600 seconds And spin-coating, followed by drying and ultraviolet curing to form a liquid crystal layer, the method of manufacturing a compensation optical element for a VA using a nematic liquid crystal, characterized in that it comprises a liquid crystal layer. The method of claim 1, The A plate is a polycarbonate film, cyclo-olefin-based film, polymethyl methacrylate film, a method for producing a compensation optical device for VA using a nematic liquid crystal, characterized in that at least one. The method of claim 1, The alignment film resin in the step (a) is a nematic liquid crystal, characterized in that at least one of unsaturated polyester resin, polyfunctional acrylate resin, polyfunctional methacrylate, urethane acrylate, epoxy acrylic resin, epoxy acrylate resin Method for manufacturing a compensation optical element for the VA used. The method of claim 1, In the step (c), the nematic liquid crystal uses a curable nematic liquid crystal polymer in which an optically active component is added to the liquid crystal polymer, and the amount of the optical activity is 5 parts by weight based on 100 parts by weight of the nematic liquid crystal polymer. Method for producing a compensation optical element for VA using a nematic liquid crystal, characterized in that from 15 to 15 parts by weight. The method of claim 4, wherein The nematic liquid crystal polymer is a nematic liquid crystal, characterized in that at least one of polyacrylate, polymethacrylate, polymalonate, polysiloxane, polyester, polyamide, polyesteramide, polycarbonate, polypeptide, cellulose Method for manufacturing a compensation optical element for the VA used. The method of claim 1, The viscosity of the alignment layer coating solution of the step (a) is a manufacturing method of the compensation optical element for VA using a nematic liquid crystal, characterized in that 1cps to 500cps. The method of claim 1, The viscosity of the liquid crystal coating solution of step (c) is a manufacturing method of the compensation optical element for VA using a nematic liquid crystal, characterized in that 1cps to 600cps. The method of claim 1, The alignment film formed in the step (a) is a thickness of 0.01㎛ to 5㎛ manufacturing method of the compensation optical element for VA using a nematic liquid crystal, characterized in that the coating. The method of claim 1, The liquid crystal layer formed in the step (c) is a thickness of 0.01㎛ to 40㎛ manufacturing method of the compensation optical element for VA using a nematic liquid crystal, characterized in that the coating. The method of claim 1, The solvent used in step (c) is chloroform, dichloroethane, tetrachloroethane, trichloroethylene, tetrachloroethylene, halogenated hydrocarbons of O-dichlorobenzene, mixed solvents of these and phenols, kentones, ethers, Preparation of compensation optical device for VA using nematic liquid crystal, characterized in that at least one of dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, sulfolane, cyclohexanone, xylene, toluene Way. The method according to any one of claims 1 to 10, Compensating optical element for VA using a nematic liquid crystal, characterized in that the manufacturing method of the compensation film for VA using the nematic liquid crystal.

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